Hyundai Motor India — very poor mileage for new i20 asta only 10 km/ lit

Address:

Pune, Maharashtra, 411041

I have used 17k kilometres, still I getting only @10 km/lit mileage.
2 times repair done by delar, but no improvement.
Very unstisfied customer. My contact [protected]
New vehicle brought last year
Last 18 months I am struggling to get the proper solution.
Can somebody provide the i20 normal mileage getting other vehicles. I tried on highway also for the mialge.